MD_Gene wrote:
Penns is a limestone stream but gets pretty warm in the summer.
Penns is a limestone influenced stream, yes, but not a true limestoner in my opinion. Most of the great big waters in the state are only limestone influenced, which those tiny springs, seeps, and smaller feeders are what make the truly great and big brown trout streams of PA great. They also have a huge impact on warm water rivers and streams because all of that limestone influence still enriches and creates great life farther downstream.
A true limestoner, say Big Spring in Cumberland County or Tea Creek in Mifflin County, certainly stays quite frigid and fishable year round.
Back to the point of the thread, however, fly-fishing and trout go hand in hand for historic reasons, which everyone knows, and it is a super effective way to catch trout. It is also super-duper fun to fly fish for trout. If the waters are cold enough for wild trout fishing or even if it is a stockie stream that gets too warm, by all means fish for trout. If it is one of our truly great large limestone influenced streams that gets questionable, then avoid if you can resist.
P.S. my roots of fishing are bass and other "warm-water" quarry. I scoffed at trout for years because I did not know of the true abundance of wild trout fishing opportunities around me. I also scoffed at fly fishing, because my naivete made the correlation of trout and fly-fishing and I thought it sounded really dumb to throw tiny feathers and furs to stocked trout. The idea of a "stocked" fish is somewhat dirty to me and always has been.
Either way, just like I overcame my ignorance eventually, I am sure that the folks who detest WW fly-fishing would totally change their mind after a tremendous day of chasing some smallmouth with a fly rod.......
int: 
